| 1 | /* |
|---|
| 2 | * ==================================================== |
|---|
| 3 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
|---|
| 4 | * |
|---|
| 5 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
|---|
| 6 | * Permission to use, copy, modify, and distribute this |
|---|
| 7 | * software is freely granted, provided that this notice |
|---|
| 8 | * is preserved. |
|---|
| 9 | * ==================================================== |
|---|
| 10 | */ |
|---|
| 11 | |
|---|
| 12 | #include "fdlibm.h" |
|---|
| 13 | |
|---|
| 14 | #ifdef __STDC__ |
|---|
| 15 | float truncf(float x) |
|---|
| 16 | #else |
|---|
| 17 | float truncf(x) |
|---|
| 18 | float x; |
|---|
| 19 | #endif |
|---|
| 20 | { |
|---|
| 21 | __int32_t signbit, w, exponent_less_127; |
|---|
| 22 | |
|---|
| 23 | GET_FLOAT_WORD(w,x); |
|---|
| 24 | |
|---|
| 25 | /* Extract sign bit. */ |
|---|
| 26 | signbit = w & 0x80000000; |
|---|
| 27 | |
|---|
| 28 | /* Extract exponent field. */ |
|---|
| 29 | exponent_less_127 = ((w & 0x7f800000) >> 23) - 127; |
|---|
| 30 | |
|---|
| 31 | if (exponent_less_127 < 23) |
|---|
| 32 | { |
|---|
| 33 | if (exponent_less_127 < 0) |
|---|
| 34 | { |
|---|
| 35 | /* -1 < x < 1, so result is +0 or -0. */ |
|---|
| 36 | SET_FLOAT_WORD(x, signbit); |
|---|
| 37 | } |
|---|
| 38 | else |
|---|
| 39 | { |
|---|
| 40 | SET_FLOAT_WORD(x, signbit | (w & ~(0x007fffff >> exponent_less_127))); |
|---|
| 41 | } |
|---|
| 42 | } |
|---|
| 43 | else |
|---|
| 44 | { |
|---|
| 45 | if (exponent_less_127 == 255) |
|---|
| 46 | /* x is NaN or infinite. */ |
|---|
| 47 | return x + x; |
|---|
| 48 | |
|---|
| 49 | /* All bits in the fraction field are relevant. */ |
|---|
| 50 | } |
|---|
| 51 | return x; |
|---|
| 52 | } |
|---|
| 53 | |
|---|
| 54 | #ifdef _DOUBLE_IS_32BITS |
|---|
| 55 | |
|---|
| 56 | #ifdef __STDC__ |
|---|
| 57 | double trunc(double x) |
|---|
| 58 | #else |
|---|
| 59 | double trunc(x) |
|---|
| 60 | double x; |
|---|
| 61 | #endif |
|---|
| 62 | { |
|---|
| 63 | return (double) truncf((float) x); |
|---|
| 64 | } |
|---|
| 65 | |
|---|
| 66 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
|---|
